Pompey’s first-half display was blasted by Kenny Jackett, despite a 2-1 success over the Hawks.
Alfie Pavey’s 29th-minute penalty was cancelled out five minutes later by Nathan Thompson to send the sides into the break locked at 1-1.
It represented a disappointing opening period for the Blues’ boss, who had again fielded his strongest side for the first 45 minutes of a friendly.
Coventry-target Conor Chaplin then clinched an 84th-minute victory in what could be his final Pompey outing.
Yet while Jackett believed the scheduled introduction of 11 changes at the interval prompted a better display, he remained unhappy over the first-half showing.
He said: ‘It was a good win and I was particularly pleased in the second half.
‘I felt we started sluggish. We didn’t show enough basic enthusiasm in the first period and, fair play to Hawks, they caused us problems.
‘Particularly the left side, we got into 2v1 situations with Lee Brown and Ronan Curtis but with all the balls into the box – and we had five or six corners – I didn't think we got enough people in there or wanted it enough and their centre-halves were first to it.
‘In the first period I didn’t think we showed enough basic enthusiasm but the second half was a very good performance, although we could have scored more.
‘Conor’s was an excellent goal and in that half there was some good link-up play between Louis Dennis, Chaplin and Oli Hawkins.
‘It was a deserved win. At times the day resembled a training day – both sides using a high amount of players – but that is what these games are for.
‘I am pleased overall to win and as the game built up, we built up with it.’
A crowd of 1,608 was present at Westleigh Park on a glorious summer’s afternoon ahead of the England quarter-final clash with Sweden.
And for Pompey, it marked successive victories, following the 4-1 triumph over Cork City the previous Monday.
Jackett added: ‘We have been back a couple of weeks and are trying to improve wherever we can.
‘It’s a balance between pushing the players and making sure we get no injuries but when the games come around we have to play them properly and play them with enthusiasm.’